Method of manufacturing brass-dust.



ALFRED sane, or s'r. crown, rmncn.

nrnrnon ofr MANUFACTURING nnnss-nus'n' No Drawing.

Specification of Letters Patent. Application filed May 6, 1909. Serial'No. 494,409.

Patented Jan. 18, 1910.

To all 'it may concern:

Be it known that I, ALFRED Sane, a sub I ject of the King of Great Britain, residing in St. Cloud, France, have invented an Improvement in the Method of Manufacturing Brass-Dust,'of which the following is a full, clear, and exact description.

My invention has relation to the manufacture of brass dust to be used for the coating of metals by cementation, for the purpose of providing. a malleable brass coating which will be perfectly homogeneous and non-porous, and which, under certain conditions and for certain purposes, is superior to a zinc coating as usually provided.

In accordance with my invention, I take a solution of -commercial copper sulfate of any'desired strength and add zinc dust very slowly thereto, preferably stirring during marks the end of the operation.

the operation. The addition of the zinc dust causes recipitation of the. copper in the form of a very fine purplish brown owder, the zinc going into solution as sul-. ate of zinc. -The zinc dust is added until the solution has a white appearance which I then filter the copper powder thus produced, the filtrate being sulfate of zinc, which is a commercial product that can be used in electrogalvanizing and for other purposes. The copper dust thus produced contains a certain proportion of copper-oxid and possibly also copper carbonate and usually other impurities. If desired, this copper dust may be washed, but as a rule, this is not necessary. It is then dried carefully under conditions to prevent undue increase in the amount of oxid, the copper in this finely divided state being readily oxidizable at moderatetemperatures. I mix the copper dust thus produced-with zinc" dust in -any desired proportion and put this mixture in a retort and heat it a shorttime at a moderate temperature, preferably altering the position of the retort or otherwise producing sufliclent agitation to result in a thorough admixture of the zinc and copper dust. The

temperature employed should not reach the point at which the zinc and copper would form into beads of brass, but must, in all cases, be kept below this point. After the retort has cooled, the contents are inthe form of a green dust, the chemical composition of which is. brass mixed with various oxids of brass and zinc, and possibly other impurities, but is, in the main, brass with a superficial film of impurity which gives the substance this green color. The dust so produced may be used in a manner similar to zinc dust in thewell known sherardizing process, although a somewhat higher temperature will be required thanis ordinarily employed in sherardizing with zinc dust as the coating material.

The copper dust used in the formation of the brass dust may be produced in otherways than by precipitation froma solution of copper sulfate, as above described, and I do not limit myself thereto. The method "described, however, forms a convenient and cheap method of producing the copper-dust. I claim:-

1. The method of manufacturing brass dust, which consists in mixing copper dust and zinc dust in a suitable retort-or vessel and heating them to a moderate temperature, substantially as described.

2. The method of manufacturing brass dust, which consists in mixing copper and zinc dust and heating them to a. temperature below that at which the zinc and copper form into beads of brass, substantially as described.

3. The method of manufacturing brass dust, which consists in precipitating -copper dust from a copper sulfate solution, and

then mixing the copper dust with zinc dust R y the admixture of zinc dust therewith,

filtering and drying the precipitated copper dust, and then mixing the copper dust substantially as described.

In testimony whereof, I have hereunto setmy hand;

SANG.

- Witnesses:

HENRY L. com, W. C. Wm'rnnrmnm.

with zinc dust and heating the mixture, 

